Noble gases with the highest ionisation energy and greater solubility in water are respectively 

Options

A. He and Ar
B. Xe and Rn
C. Xe and He
D. He and Xe

Answer

To solve the question regarding noble gases with the highest ionization energy and greater solubility in water, we will analyze the properties of noble gases systematically.

### Step-by-Step Solution:

1. **Identify Noble Gases**: The noble gases include Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn).

2. **Determine Ionization Energy**:
- Ionization energy is the energy required to remove an electron from an atom in the gas phase.
- Among the noble gases, Helium has the highest ionization energy. This is due to its small atomic size and the strong attraction between the nucleus and the electrons.
- As we move down the group in the periodic table, the ionization energy decreases due to increased atomic size and shielding effect.

3. **Determine Solubility in Water**:
- Solubility of noble gases in water generally increases as we go down the group.
- This is due to the increasing polarizability of the larger noble gas atoms, which allows for greater interaction with water molecules.
- Among the noble gases, Radon (Rn) is known to have the highest solubility in water, although it is less commonly discussed compared to Xenon (Xe) and Krypton (Kr) which also exhibit significant solubility.

4. **Conclusion**:
- The noble gas with the highest ionization energy is **Helium (He)**.
- The noble gas with greater solubility in water is **Radon (Rn)**.

Thus, the answer to the question is:
- Highest Ionization Energy: **Helium (He)**
- Greater Solubility in Water: **Radon (Rn)**

### Final Answer:
Helium (He) has the highest ionization energy, and Radon (Rn) has the greater solubility in water.

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